Looks cool
Just a few comments though:
You'll get more responses for this in the Painting and Modelling sub-forum, with a less vague title ("Ork warboss conversion!" For example).
A closer picture would let us see the conversion better.
I think Warbosses in
40k tend to be on 40mm rounds rather than 25mm, but it shouldn't really be much of an issue I think.